1. Technical Field
The present disclosure relates to photoresistors and, more particularly to a photoresistor incorporating carbon nanotubes.
2. Description of Related Art
A photoresistor or light dependent resistor is a resistor whose resistance decreases with increasing incident light intensity.
In related arts, a photoresistor includes an active semiconductor layer deposited on an insulating substrate, and two metal contacts placed separately on the exposed area of the semiconductor layer. Within the photoresistor structure, the resistance of the semiconductor material itself is a key issue. To ensure the resistance changes resulting from the light dominate, the resistance of the two metal contacts is minimized. To achieve this, the area between the two metal contacts is in the form of a zigzag or interdigital pattern. This keeps the distance between the two metal contacts small, which reduces the resistance and enhances the carriers gain.
However, because the metal contacts are impenetratable by light, the exposed area of the semiconductor is still small and the sensitivity of the photoresistor to the weak light is low. Furthermore, the photoresistor cannot be used to detect the polarized light without external polarizing elements.
What is needed, therefore, is to provide a photoresistor which is more sensitive to the weak light and can also be used to detect polarized light without external polarizing element.